ENZYMATIC EXTRACTION OF SHEA BUTTER: OPTIMIZATION STUDY USING RESPONSE SURFACE METHODOLOGY

Enzymatic extraction of shea butter (SB) from its kernel was undertaken and characterized using standard methods. Fourier transform infrared spectroscopy (FTIR) was used to determine the functional group of the extracted SB. In a preliminary study, SB was extracted using a mixture of enzymes, which had in equal proportion pectinase, a-amylase, cellulase, glucoamylase and xylanase. The operating parameters of extraction temperature (50 degrees C), time (180 min), water/seed ratio (6: 1, w/w) and pH (5) were used for the study, which yielded 32.71% SB. However, using each of the enzymes for the extraction under the same operating parameters, pectinase yielded 31.40%, which was higher compared to the yield of other enzymes. Hence, pectinase was used to optimize the operating parameters using response surface methodology. A box behnken design was adopted to evaluate the effect of each of the parameters on percentage yield of SB. The result indicated that the parameters had significant effect on the yield of SB with R-2, F and p value of 0.9994, 1,375.24 and 0.0001 respectively. The interactions of water/seed ratio with other parameters showed a significant effect at p<0.0001. Based on this model, maximum yield of 42.95% SB was obtained at 50 degrees C, 180 min and 7: 1 water/seed ratio (w/w). The physico-chemical properties of the extracted SB compared favorably well with SB extracted using other methods. The FTIR result indicated that the enzymatic treatment did not affect the chemical composition of the butter. Accordingly, enzymatic extraction can serve as a suitable method for SB extraction.